How to clean a dehumidifier in 5 easy steps – for maximum efficiency

Using a dehumidifier is the most effective solution for removing excess moisture from the air, but regular cleaning is a must

bordered image of Swan dehumidifier with clothes nearby and a decorative table to support a guide on how to clean a dehumidifier
(Image credit: Emily Smith)

Knowing how to clean your dehumidifier effectively not only ensures it will always run to maximum efficiency but will also prolong the life of this invaluable household device.

Investing in one of the best dehumidifiers is a great idea when it comes to the winter months when damn and moisture invade our homes. From preventing condensation on windows and providing a cheaper alternative to drying your clothes indoors, dehumidifiers are a multi-functional appliance in the home. 

With all the work a dehumidifier puts in, it’s no surprise that keeping the machine clean will not only prolong the device's life but also allow it to function at maximum efficiency keeping the mould safely away. 

We spoke to air purity experts for the very best way to approach the task and keep your dehumidifier in the very best shape possible. 

How to clean a dehumidifier 

As with the best air purifiers, the key to maintaining a proper level of humidity in your home comes down to having a clean and fully functioning appliance. 

There are several different parts to concentrate on and be aware of, including the filter, which needs to be cleaned regularly. 

"The air filter is crucial in protecting the parts inside the dehumidifier and cleaning the dry air in the room. If the air filter is dirty or covered in dust, the dehumidifier will not do its job as the air will not be able to pass through," explains Chris Michael, managing director at Meaco

"There are several common problems that can arise from a filthy air filter: the unit will not be able to collect water, the unit will continue to work but reduce the humidity level insufficiently/there will be little water in the tank, or it can even result in a noisy dehumidifier." Especially important for the best bedroom dehumidifiers, where noise levels are everything.

To answer the question of how to clean a dehumidifier correctly you'll need the following tools, depending on your device: 

  • Warm soapy water
  • A clean microfibre cloth
  • A vacuum cleaner (optional)
  • A small soft brush such as a toothbrush (optional)
  • White wine vinegar (optional)
  • A screwdriver if screws need to be removed with casing

1. Unplug the appliance

Picture of appliance unplugged with plug heald in front of device

(Image credit: Emily Smith)

As with any electrical appliance, for safety reasons, it is vital to switch off and unplug the machine from the electricity supply before attempting any element of cleaning especially here where water is such a major component. 

Chris Michael
Chris Michael

Chris Michael is the expert co-founder of Meaco. Since its launch in 1991, Meaco has become a leading UK provider of air treatment products and the brand’s products have won a wealth of industry and design awards internationally.

2. Empty and clean the water reservoir

Dehumdifier water resevoir being emptied into a white sink

(Image credit: Emily Smith)

Unless you’re collecting and pumping water from a dehumidifier hose directly into a drain, the reservoir will need to be emptied regularly.

Every dehumidifier has a removable container that collects moisture from contracted air. This should be emptied every day. However, this can vary depending on the relative humidity levels in the space.

When cleaning a dehumidifier, empty the cartridge and submerge it in warm soapy water to remove any build-up of limescale or bacteria from polluted air particles.

"Use a microfibre cloth with a little dish soap to wipe down the interior of the reservoir," suggests Ivan Ivanov of End of Tenancy Cleaning. "This way, any potential mould build-up will be removed, meaning the dehumidifier is healthier and also works more efficiently." 

3. Clean the dehumidifier filter

The dehumidifier filter

(Image credit: Emily Smith)

Knowing how to clean a dehumidifier filter varies by model and manufacturer but essentially the goal is to remove dust and debris from all components to ensure air runs through freely. Clogging and blockages within the filter will hinder the process.

"To clean the air filter, carefully vacuum it, or if the suction is too strong, you can also use a damp cloth and warm soapy water, to gently wipe the dirt away," suggests Chris. "The water should be no hotter than 40°C. Once all the dust has been rinsed off, simply dry the dehumidifier filter with a tea towel before placing it back in the dehumidifier."

"If the filter is very fine, use a clean leftover toothbrush! The small bristles work perfectly for getting into those tough-to-reach spots," adds Ivan.

"Please note that if the dehumidifier has dual use as an air purifier it is likely to have a HEPA filter," warns Chris. "These filters are made up of a very delicate fine mesh of fibres that capture organic matter such as mould spores and other allergens. Manual cleaning is not recommended. A HEPA filter should be thrown away and replaced every six months."

To access the filter you may need to remove the outer casing of the machine first while others slide out of the back of the unit, something you may wish to know before buying a dehumidifier. Always consult your user manual if you are unsure.

4. Inspect the dehumidifier coils

The internal coils of the dehumidifier

(Image credit: Emily Smith)

How a dehumidifier works can be explained by the action of sucking air currents into coils via a fan. The warm air shrinks as it feeds through the chilled coils of the machine, and water molecules are squeezed out and collected in a compartment inside the machine. 

If the coils aren't kept clean and dust-free the build-up that accumulates on the surface will make the coils work harder to either absorb or release heat, resulting in less efficient operation.

To clean the coils of a dehumidifier to get rid of dust, vacuum the outer tubes or carefully brush away any dust and debris with a clean, dry brush. 

On the topic of cleaning coils, Chris advises against consumers opening up a mains-operated appliance and points out it is illegal for non-FGas registered people to work on a refrigerant-based product according to government guidelines.

5. Finish by wiping down the dehumidifier casing

image of womans hand wiping down the exterior of a dehumdifier

(Image credit: Emily Smith)

Once the inner components are clean, dry, and have been replaced, refit the outer casing of the dehumidifier. Then, use a damp, clean microfibre cloth to wipe down all surfaces, paying special attention to the suction pump.

Explaining why it's important to give the exterior a final wipe down Ivan explains: "The dehumidifier actively sucks in air, meaning all of the dust and dirt that’s in the air follows suit. Sometimes, the dust doesn’t make it all of the way through to the filter, settling on the exterior of the dehumidifier instead."

Once this is done allow the unit to completely dry, before plugging the appliance back into the mains to start using it once again. 

Top tip: "If the dehumidifier is not going to be used for a period of time make sure to keep the device stored in a dust-free area away from direct sunlight, ideally covered in a sheet of plastic," says Chris. This ensures your newly cleaned machine stays in perfect working order, dust-free for when you need it next.


Do dehumidifiers need to be cleaned?

The short answer is yes. To keep a dehumidifier running to peak performance it will require regular upkeep and occasional deep cleaning, using the routine above, to continually improve the air quality of your home most efficiently. 

Particularly the filter. "The air filter is a driving force behind the dehumidifier, with the bucket collecting water, the air filter is pivotal in extracting dust and other large particles from the air in your home. If the air filter is not properly cleaned it can result in the dehumidifier stopping functioning," explains Chris.

But, just like the big question of how often should you clean your house, the time between cleaning this invaluable home appliance depends on how often you use it. If your dehumidifier is in optimum use, add it to the fortnightly deep-clean list that also reminds you to clean your dishwasherclean your washing machine, and clean your oven

A dehumidifier in a living room on wooden laminate floor with the water tank removed to show how to clean a dehumidifier

(Image credit: Getty Images | Mary Violet)

Can I clean a dehumidifier with vinegar?

If you are looking for natural options for how to clean a dehumidifier, a blend of water and white vinegar can be used instead of soapy water.

"White wine vinegar is a godsend when it comes to cleaning. A weak form of acetic acid, it effectively kills mould bacteria and germs" says professional cleaner Lynsey Crombie, TV's Queen of Clean.

Lynsey explains how to try cleaning with vinegar: "Mix 120ml / half a cup of white wine vinegar and 50g/ 1 quarter cup of bicarbonate of soda with 2 litres / 8 cups of water. Mix until fully dissolved. Decant into a labelled spray bottle and use it to clean with ease."

This solution can be used to remove mould, bacteria, and dust debris from the outer casing of the dehumidifier as well as the filter, coils, and water collector.

How do I clean the dust out of my dehumidifier?

Gently vacuum off the top layer of dust from the outer casing of the dehumidifier. Then, use a soft-bristled brush or microfibre cloth to wipe down the unit. To remove dust from inner components follow the numbered steps above.

How often should I clean a dehumidifier? 

"Household dehumidifiers typically come with a life-long filter which should not have to be replaced, except for reasons of wear and tear," explains Chris. "With regular use, the filter will collect dust and dirt particles, meaning that it must be cleaned every two weeks, at minimum. Not doing so could invalidate the dehumidifier’s warranty.“

However, this depends on how much the appliance is used. If your dehumidifier is in constant use we recommend emptying the tank daily and cleaning the filter weekly.

A black tiled floor with a dehumidifier plugged in to show the first step when looking how to clean a dehumidifier

(Image credit: Getty Images | Mario Guti)

The difference between an electric dehumidifier and a non-electric dehumidifier is price point and performance. Put simply, you get what you pay for and investing more money in an electric dehumidifier means your air humidity will remain less for longer. But of course, factoring in how much it costs to run a dehumidifier may influence which model you choose. 

Rachel Homer

Rachel Homer has been in the interiors publishing industry for over 15 years. Starting as a Style Assistant on Inspirations Magazine, she has since worked for some of the UK’s leading interiors magazines and websites. After starting a family, she moved from being a content editor at Ideal Home to be a digital freelancer and hasn’t looked back. 

With contributions from